Same-sex military couples are not eligible for many benefits that heterosexual married couples in the military receive, including housing and medical care. But the Supreme Court could redefine the federal status of gay marriage next year.

Washington — When Chief Warrant Officer Charlie Morgan returned from a year-long deployment to Kuwait with the New Hampshire National Guard in 2010, her doctor didn’t have good news. The breast cancer thought to be in remission, the physician said, had returned, and the diagnosis was terminal.

That’s when Morgan began a new battle – to make sure her wife and their daughter receive the same survivor benefits that would go to any other married couple with children.

The US Supreme Court’s decision to take up the Defense of Marriage Act (DOMA) could have a considerable impact on the benefits of same-sex spouses of service members, who were largely invisible to the military until the repeal of “don’t ask, don’t tell” (DADT).

But for the partners of gay troops, the impact of the repeal has been less sweeping and more ambiguous.

Even when gay couples are legally married under state law, for example, Section 3 of DOMA forbids the US government from treating such military couples as married.

And so they are not eligible for the kinds of benefits that heterosexual married couples receive in the military, including housing, medical care, and in the case of Morgan and others, survivor benefits should they die while serving their country.

DOMA Section 3 is the specific measure that will be reviewed by the Supreme Court in March.

Passed by Congress in 1996, the law declares that the word “marriage” means only a legal union between one man and one woman and that the word “spouse” refers only to a person of the opposite sex who is also a husband or wife.

As a result, under federal law, the benefits of marriage can go only to a person of the opposite sex, regardless of state law.

The Obama administration said last year that it would enforce the law, but would no longer defend it in court.

Should DOMA Section 3 be struck down by the Supreme Court, “My sense is that same-sex couples who are married under state law would be treated exactly the same as married couples are for the purposes of treatment on military installations and for benefits,” says Robert Tuttle, a law professor at George Washington University.

While enlisted soldiers are permitted to live off base if they are married, unmarried soldiers are often required to live in barracks on base.

Yet in some cases where gay service members are married under state law, they have “been forced to live on base, while their husband or wife has to live off base,” Mr. Stokes says. “And so they have to incur the cost of two households in these situations, so there are some real financial hardships associated with it.”

In addition to not being eligible for housing allowances and government medical insurance, same-sex military couples often find a litany of “daily indignities” the most difficult, Stokes says.

Opposite-sex spouses of troops, for example, are allowed to shop at the base grocery store, known as the commissary. Same-sex spouses often cannot, though base commanders sometimes make exceptions to this rule.

Stokes recalls a same-sex spouse who had permission from base command to shop at the commissary, but only to buy items for the child she had with her partner.

When she went to pay for the groceries, the cashier made her justify each item and why it was specifically for her child. “Those sorts of things can sometimes be as psychologically damaging as not having health care,” he says. “Because it’s so publicly humiliating.”

Morgan recalls a similar incident. After the cancer diagnosis, she and her wife, Karen Morgan, were on a “bucket list” trip to Hawaii with their daughter, Casey.

They went to the commissary to buy some food, but Morgan's wife was not permitted to enter because, as a same-sex spouse, she is not entitled to a base ID card under DOMA.

“I had my ID card, and Casey had hers, but Karen was told she couldn’t go in. Karen does all the shopping for our family, and Casey was asking, ‘Mama, why can’t Mommy come?’ ” Morgan says.

“It was embarrassing – plus, as the caretaker in our family, Karen is the one who knows what we like to eat, not me.”

Nor is her wife entitled to Tricare military medical insurance, an expense that costs the family an additional $700 a month, Morgan says. “We cannot afford that,” she says.

Upon her death, she adds, her daughter, Casey, will get survivor life insurance and what the military calls a death gratuity, in addition to Social Security benefits.

While an opposite-sex spouse would also be eligible for these benefits, Karen is not. “I earned these benefits serving my country,” says Morgan, who has been in a civil union with her wife since 2000, and married to her since 2011, after DADT was repealed. “It’s the same fears anyone has for their family: I just want them to be taken care of.”

The Supreme Court’s decision to take up DOMA fills her with hope. “I’m very excited that they took up the legislation,” Morgan says. “It makes me very proud.”